Dr. Joseph J. Wakshlag, DVM

Associate Professor of Clinical Nutrition

Dogs suffering from kidney disease need to have a few lifestyle changes implemented, including a change in diet. Find out here how a prescription diet can help with your dog's kidney condition.

Dogs with kidney disease require a special diet to slow the progression of the disease and to prevent other health problems associated with kidney disease. Because diseased kidneys must work much harder to filter out toxins, and this throws off their normal hormone balance, dogs can get high blood pressure, phosphorus buildup in the blood, and/or B-vitamin deficiency. Diet is an important component of treatment and a prescription diet, such as Hill's k/d, can keep the disease from getting worse and encourage the proper balance of vitamins and minerals.

Switching to a prescription kidney food should occur gradually over one to two weeks. And you should always follow the directions of your veterinarian. Vets usually recommend the best diet based on your dog's stage of kidney failure, but there are some common features of most kidney-friendly diet foods:

Lots of Water

Dogs with kidney disease need much more water because their kidneys are more active trying to eliminate toxins. Kidney diet foods may come in either a canned or dry version.

Canned food is preferred, because it has significantly higher moisture content

Especially when using dry food, it will be important to provide plenty of clean, fresh water for your dog. You can even soak your dog's dry food in water to encourage water intake.

Kidney Disease Diet Nutrients (Compared to Regular Food)

Why

Protein

Less (kidney diets are 13-18% protein)

Reduces protein buildup

Fat

More (kidney diets are 16-20% fat)

Easier to digest than protein for energy

Carbohydrates

More (first ingredient)

Easier to digest than protein for energy

Phosphorus

Less

Slows disease progression

Sodium

Less

Reduces blood pressure

Omega 3 Fatty Acids

More

Reduces blood pressure and inflammation in kidneys

Vitamins and Extra Antioxidants

More

Controls cell damage and improves immune system

Reduced Protein

Protein in kidney disease diets is a matter of some controversy: reduced protein in advanced kidney disease can keep protein from building up, but when the disease is in its early stages, some protein can still be processed and it is an essential part of the diet. If protein is too high your dog can build up byproducts of protein that the kidney would usually filter out. Buildup of the metabolite called urea is problematic when very high. It's part of what makes a dog feel sick when suffering from kidney disease.

Prescription diets have decreased levels of protein, so you should work with your vet to determine the best food with the right amount of protein based on your dog's stage of illness. At all stages, it's very important to feed your dog high quality protein to rebuild unhealthy cells.

Increased Fat and Carbohydrates

Even with less protein, dogs will still need fat and carbohydrates for energy. Fat and carbohydrates are easier to digest, so you will see higher amounts in kidney disease foods than in regular dog food. Fat in the diet usually increases the palatability of the food too, making your dog keen to eat enough so they won't lose weight.

Reduced Phosphorus

When kidneys are less effective, they can allow phosphorus to build up in the blood. Phosphorous buildup can lead to decreased kidney function and increased symptoms of kidney failure. Most phosphorus comes from protein and kidney diets usually have a reduced level of phosphorus to combat this buildup.

Reduced Sodium

When kidneys are struggling, some of the hormonal balance related to kidney blood pressure will be off. This leads to mild to modest hypertension, which can lead to high blood pressure. And too much sodium is not good for high blood pressure. Prescription foods have lower levels of sodium, but they are not sodium-free. Dogs still need sodium in their diets for healthy nervous system function and to prevent dehydration.

Increased Water-Soluble Vitamins and Other Antioxidants

Because dogs with kidney disease drink more water and eliminate more often, they also are eliminating important vitamins, like vitamins B and C. Luckily, prescription diets try to counter this with increased amounts of these commonly deficient vitamins. Antioxidants are also good for controlling cell damage and improving immune system health.

Omega-3 Fatty Acids

Long-chain omega-3 fatty acids, such as those found in fish oils, are also effective at reducing blood pressure and kidney inflammation. They can improve blood flow and improve general kidney health. While these should be included in prescription kidney food, they may not be present in high enough amounts, so your vet may recommend a supplement.

More on Kidney Disease

This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian. It has however been reviewed for accuracy by Dr. Joe, a board certified veterinary nutritionist and graduate of Cornell University's program for Veterinary Medicine.